There are presently over 300 million customers worldwide for cellular telephones and other wireless devices. A significant percentage of these wireless devices are being used as a “data pipe” (i.e., voice traffic is not the primary function). Within the United States, cellular service is offered by cellular service providers, by the regional Bell companies, and by the national long distance operators. The enhanced competition has driven the price of cellular service down to the point where it is affordable to a large segment of the population.
The current generation of cellular phones is used primarily for voice conversations between a subscriber device (or wireless device) and another party through the wireless network. A smaller number of wireless devices are data devices, such as personal digital assistants (PDAs) equipped with cellular/wireless modems. Because the bandwidth for a current generation wireless device is typically limited to a few tens of kilobits per second (Kbps), the applications for the current generation of wireless devices are relatively limited. However, this is expected to change in the next (or third) generation of cellular/wireless technology, sometimes referred to as “3G” wireless/cellular, where much greater bandwidth will be available to each wireless device (i.e., 125 Kbps or greater). The higher data rates will make Internet applications for wireless devices much more common. For instance, a 3G cell phone (or a PC with a 3G cellular modem) may be used to browse web sites on the Internet, to transmit and receive graphics, to execute streaming audio or video applications, and the like. In sum, a much higher percentage of the wireless traffic handled by 3G cellular systems will be Internet protocol (IP) traffic and a lesser percentage will be traditional voice traffic.
Real-time streaming of multimedia content over Internet protocol (IP) networks has become an increasingly common application in recent years. As noted above, 3G wireless networks will provide streaming data (both video and audio) to wireless devices for real time applications. A wide range of interactive and non-interactive multimedia Internet applications, such as news on-demand, live TV viewing, video conferencing, live radio broadcasting (such as Broadcast.com), and the like, will provide “real time” data streaming to wireless devices. Unlike a “downloaded” video file, which may be retrieved first in “non-real” time and viewed or played back later, real time (or streaming) data applications require a data source to encode and to transmit a streaming data signal over a network to a receiver, which must decode and play the signal (video or audio) in real time.
Triangulation delay in a telecommunications network is delay that is caused by having to send a message over a longer network path than would otherwise be necessary. To illustrate the concept of triangulation delay consider an example of a cellular telephone that is capable of sending and receiving Internet protocol (IP) packet based voice and data messages. The home agent for the data packet network of the cellular telephone is located in New York, N.Y. (Site A). Further assume that the user of the cellular telephone (whom we will call “Eric” ) is temporarily located in Seattle, Wash. (Site B). In presently existing wireless data packet networks the data packets of the call to be delivered to Eric's cellular telephone must first go to Eric's home agent at Site A in New York and then be relayed to Eric at Site B in Seattle. If a friend of Eric's (whom we will call“John”) calls Eric from Los Angeles, Calif. (Site C), then the data packets of the call from John will be routed from Site C to Site A and then from Site A to Site B.
The time to send data packets from Site C to Site A and then from Site A to Site B is longer than the time required to send data packets directly from Site C to Site B. The difference in time is referred to as “triangulation delay.” The direct connection from Site C to Site B represents one side of a triangle. The indirect connection from Site C to Site B through Site A represents two sides of a triangle. Therefore the direct connection will always require less travel time. The triangulation delay includes time spent at Site A (“overhead time”) to redirect the data packets in the call to Site B. Triangulation delay lessens the efficiency of the network.
The volume of telecommunications network traffic is projected to grow significantly. It is estimated that there will be approximately five hundred million (500,000,000) IP addresses in existence by the year 2005 (thirty percent (30%) of an estimated 1.65 billion users) and that there will be one billion (1,000,000,000) IP addresses in existence by the year 2010. As the volume of network traffic continues to grow, triangulation delays will also continue to increase. At some point the reduced efficiency of the network caused by triangulation delays will become significant.
There is therefore a need in the art for an improved telecommunications network that is capable of avoiding triangulation delay. In particular, there is a need for an improved system and method that routes network traffic in a manner to avoid triangulation delay.